Abrasive structure



June 19, 1934. SCHNElDER 1,963,154

ABRASIVE STRUCTURE I Filed May 2, 1931 2 Sheets-Sheet l 1% Trims J SCHNEIDER sB VZMMM W/JWE Avi a/Ways ABRASIVE STRUCTURE Filed May 2, 1931 2 Sheets-Sheet 2 [n we)?! or MTHMS J Saws/51pm? AZ [or/h ys Patented June 19, 1934 i 1,963,154

UNITED STATES PATENT OFFICE ABRASIVE STRUCTURE Mathias J. Schneider, Chicago, Ill. Application Mai 2, 1931, Serial No. 534,475 1 Claim. (01. 51 193) My invention relates to grinding machinery, weave, as indicated diagrammatically in Figand includes among its objects and advantages ure 4. The first step in building up the wheel the provision of an improved abrasive structure. consists in spreading a thin layer of the abrasive In the accompanying drawings: filler upon a supporting structure or within a Figure 1 is a side elevation of an abrasive wheel suitable mold. One of the disks 22 is then placed 60 according to the invention; upon the layer of abrasive, after which a second Figure 2 is a sectional view along the line 2-2 layer of abrasive filler is placed upon the fabric of Figure 1; disk. The alternate addition ofthe disks 22 Figure 3 is a diagrammatic view illustrating and the abrasive filler is continued until a wheel a method of constructing a wheel; has been built up which will be of the desired 65 Figure 4 is a fragmentary diagrammatic view thickness after compression. of the fabric employed; After the disks and the abrasive filler have Figure 5 is a diagrammatic side view of a been arranged as shown in Figure 3, pressure is fabric disk; applied to the wheel. The layers of abrasive Figure 6 is aii edgejview; filler should be of such thickness that when 70 Figure 7 is a side elevation of a wheel havin pressure is applied to the wheel the abrasive reenforcing elements radially aligned; filler will become uniformly incorporated and Figure 8 is a side elevation of a wheel having intimately mixed with the fabric disks. In Figa plurality of reenforcing sectors arranged in ure 2 I have shown the uniform texturewhich overlapping relation; I attain in the finished article. The materials 75 Figure 9 is an edge View of the wheel shown are mixed in such manner that I entirely elimiin Figure 8; I v nate definite areas of concentrated abrasive Figure 10 is a diagrammatic view of a fabric filler or fabric'material in the wheel. This feareenforcing material helically wound; ture provides a wheel having uniform abrading 5 Figure llis a side elevation of a wheel embodycharacteristics. It also provides a wheel of unis0 ing pieces of reenforcing fabric arranged in diform strength throughout every portion of the agonal relation with respect to the sides of the disk. wheel; The abrasive filler may be incorporated in a Figure 12 is an edge view of the wheel shown fabric matrix by the use of a spray gun in'lieu in Figure 11; of the procedure illustrated in Figure 3. The 95 Figure 13 is a sectional view of a wheel emspray n dis h s th ab asive fill w th bodying shredded reenforcing material intisufiicient force to thoroughly mix the filler with mately mixed with the cement; and the fabric. In building up a wheel when a spray Figure 14 is an edge view of a modified form gun is used, several disks can be impregnated at -01 wheel illustrating a one-piece reenforcing eleone spraying, and repeated sprayings will build ment. up any desired thickness. In either case pres- In the embodiment of the invention selected sure may be thereafter applied to the wheel to for illustration, the wheel comprises a disk 10 intimately mix the abrasive filler with the fabric having a central opening 12 lined with a metal matrix.

sleeve 14. A shaft 16 passes through the sleeve As illustrative of the class of cements lnclud- 95),

14 and is fixed to the disk 10 by means of a nut ing Portland cement, oxychloride and oxysul- 18 which, when tightened, clamps the disk bephate cements, and various plasters which I refer tween flanges 20. The flange 20 opposite the to as synthetic cements as distinguished from nut 18 may rest against an abutment 21 shaped agglutinative cements, such as gums and glues,

like a nut, by means of which the shaft 16 may I will now give the exact procedure for an 100 be held against rotation. oxysulphate cement.

The disk 10 comprises a fabric matrix having I mix with a charge of abrasive, magnesium an abrasive filler uniformly incorporated with oxide amounting to substantially of the and mixed through it. The filler comprises in amount of abrasive by weight.

50 part a synthetic cement material which firmly To this I add a magnesium sulphate solution unites the filler with the matrix. In building made up as follows: To a given charge of magup the wheel illustrated in Figures 1 and 2 I nesium sulphate add either 1% of sodium citrate take a plurality of fabric disks 22 which are at or of citric acid and dissolve the entire mass first separated by thin layers of plastic abrasive in water to make up a solution having a specific filler 24. The disks.22 should be of an open gravity of 28 Baum or 1.239 absolute.

Of this magnesium sulphate solution I add to the dry mixed mass of abrasive and magnesium oxide enough to have the magnesiumsulphate from 15 to' 100% by weight of the charge of abrasive and magnesium oxide. Where the material is applied to the fabric with a spray gun I have secured good results with of magnesium sulphate, and where it is incorporated by molding or tamping I have secured good results with 80% magnesium sulphate.

- After the wheels have been formed, they are permitted to dry, which finally conditions the wheels. I have found that the wheels dry within a short time under normal atmospheric conditions, and that it is unnecessary to subject the wheels to any treatment such as conditioned air.

In Figure 7 I have shown a wheel comprising in part a plurality of fabric members 26 which are radially aligned and embedded in the abrasive filler. This type of wheel is particularly efficient in cases where the work to be ground is applied to the sides of the wheel.

The wheels illustrated in'Figures 8 and 9 are constructed from a plurality of fabric sectors 28 arranged in overlapping relation. In viewing Figure 9 it will be noted that the sectors are arranged in the form of disks between layers of abrasive filler 30 The sectors comprising one disk overlap the sectors comprising the adjacent disk. After a wheel has been built up as shown in Figure 9, pressure is applied to the wheel for intimately mixing the abrasive filler with the fabric.

In Figure 10 I have shown an alternative fabric construction. The fabric comprises a strip or ribbon 32 which is helically wound for receiving thin sheets of-plastic abrasive filler between the convolutions of the fabric.

The wheel illustrated in Figures 11 and 12 comprises a plurality of fabric sectors 34 which are diagonally arranged with respect to the sides of the wheel. Figure 12 shows a wheel preparatory to receiving pressure for intimately mixing the abrasive filler with the sectors 34.

In Figure 13 I have shown a wheel 36 having the abrasive filler intimately mixed with a shredded material. The shredded material is intimately mixed with the abrasive filler and the wheel is subsequently formed from the previously mixed material. The shredded material may also be mixed with the abrasive filler during its discharge with the abrasive filler from a spray gim. The spray gun may be adjusted for varying the amounts of the different materials during the spraying process. In cases where the spray gun is employed for building up the wheels Ifind that the magnesium sulphate may be varied between 15 to by weight of the charge of abrasive and magnesium oxide. 30 to 60% may be used in connection with the spray gun methodwithout necessitating the application of pressure to the wheel. In all cases where the magnesium sulphate content varies between 15 to 30%, pressure in excess of twenty pounds per square inch must be applied.

I have found that the abrasive filler may be incorporated in a fabric matrix comprising a single piece as indicated in Figure 14. In this form the abrasive filler is preferably embedded in the fabric 38 by means of a spray gun. The wheel may also be formed without the use of a spray gun by employing an abrasive filler of. a semil iquid condition so that the fabric will absorb the filler.

A soft or hard wheel may be constructed by respectively decreasing or increasing the proportion of magnesium oxide. Wheels constructed in accordance with the invention are reenforced in such a manner that the wheels may be operated at high speedswithout danger of breakage. The wheels also have high abrading properties. and do not give of! offensive odors of chlorine or other compounds when used for grinding purposes.

Without further elaboration the foregoing will 'so fully explain my invention that others may,

by applying current knowledge, readily adapt the same for use under various conditions of service.

I claim: An abrasive structure comprising a reinforcing structure, and an abrasive filler uniformly incorporated in said reinforcing structure, said filler comprising at least in part a binder made up of magnesium oxide, magnesium sulphate, sodium citrate and citric acid.

MATHIAS J. SCHNEIDER. 

